Apparatus for piecing a thread in an open-end spinning unit

ABSTRACT

Apparatus for piecing a thread end in an open-end spinning unit having a spinning rotor with a ring of open-up fibers including opening means having friction tool means for fraying the thread end at a predetermined location and a device for returning the thread end into the spinning rotor after fraying thereof by the friction tool means. Preferred embodiments of the friction tool means include rotatably mounted friction tool members as well as non-rotatably mounted friction tool means. The friction tool means have roughened surfaces in the form of a file in some embodiments, while having brush like surfaces in other embodiments. Various means are provided for adjusting the position of the friction tools and for operating same to effect roughening or fraying of the thread, including surfaces designed to effect a severing of the thread after a preliminary roughening. Clamping devices are also provided for clamping the thread at opposite sides of the friction tool, which clamping devices are movable with respect to one another to effect severing of the thread after being frayed.

United States Patent 1 Stahlecker et al.

[ Dec.9,1975

[ APPARATUS FOR PIECING A THREAD IN AN OPEN-END SPINNING UNIT [76]Inventors: Fritz Stahlecker,

Josef-Neidhart-Strasse 18, D 7341 Bad Ueberkingen, Gerr'nany; HansStahlecker, Haldenstrasse 20, D 7334 Suessen, Germany 22 Filed: on. 10,1974 21 Appl. No.: 513,849

[30] Foreign Application Priority Data Oct. 10, 1973 Germany 2350843[52] US. Cl. 57/34 R; 57/58.89 [51] Int. Cl. D01H 7/00;DO1H 1/12;DO1H15/00 [58] Field of Search 57/22, 34 R, 34 T1", 58.89,

[56] References Cited UNITED STATES PATENTS 2,515,172 7/1950 Abbott57/159 3,163,976 l/l965 Juillard 57/58.89 3,425,205 2/1969 Landwegrkampet al. 57/58.89 3,492,804 2/1970 Landwehrkamp et al..... 57/58.89 X3,626,440 12/1971 Harmon 57/34 R 3,722,198 3/1973 Gotzfried 57/58.89

Primary Examiner-Donald E. Watkins Attorney, Agennor FirmCraig &Antonelli ABSTRACT Apparatus for piecing a thread end in an open-endspinning unit having a spinning rotor with a ring of open-up fibersincluding opening means having friction tool means for fraying thethread end at a predetermined location and a device for returning thethread end into the spinning rotor after fraying thereof by the frictiontool means. Preferred embodiments of the friction tool means includerotatably mounted friction tool members as well as non-rotatably mountedfriction tool means. The friction tool means have roughened surfaces inthe form of a file in some embodiments, while having brush like surfacesin other embodiments. Various means are provided for adjusting theposition of the friction tools and for operating same to effectroughening or fraying of the thread, including surfaces designed toeffect a severing of the thread after a preliminary roughening. Clampingde vices are also provided for clamping the thread at opposite sides ofthe friction tool, which clamping devices are movable with respect toone another to effect severing of the thread after being frayed.

29 Claims, 11 Drawing Figures US. Patent Dec. 9 1975 Sheet 1 of 23,924,394

US. Patent Dec. 9 1975 Sheet 2 of 2 APPARATUS FOR PIECING A THREAD IN ANOPEN-END SPINNING UNIT BACKGROUND AND SUMMARY OF THE INVENTION Thisinvention relates to an apparatus for piecing a thread in an open-endspinning unit with a device for returning the thread end into a spinningrotor containing a ring of opened-up fibers. Related applications ofapplicants to be filed herewith, having similar titles as the presentapplication, and based on U.S. applications Ser. Nos. 513,775 and513,776, both filed on even date herewith, are incorporated herein tothe extent necessary for a complete understanding of the presentinvention.

Piecing of a thread is necessary in an open-end spinning unit if themachine is to be started after a standstill or if a thread break is tobe eliminated. For this pur pose, a thread end of the already spunthread is returned into the spinning rotor, attached to the fiber ringpresent therein, and again withdrawn. Devices have been contemplatedwhich execute this procedure semiautomatically or fully automatically.Certain conditions must be maintained exactly in this process, such as,for example the dimensioning of the length of the thread end to bereturned, or the selection of the instant, and the speeds, at which thethread end is again withdrawn. In practice, it was found that thepiecing zones lead to difficulties, since they are of a lower qualitydue to the fact that their tear strength is lower than in the remaininglength of thread, on the one hand, and thickening of the yarn occursfrequently at the piecing point, on the other hand. Therefore, in mostinstances, subsequent rewinding steps are required in order to removethe piecing points and replace same by knots. This additional operatingstep requires an increased expenditure in machinery and time.

The invention is based on the problem of constructing an apparatus ofthe type mentioned hereinabove so that the piecing procedure is improvedby avoiding thickened portions in the yarn and reductions in tearstrength in the zone of the piecing points. The invention contemplatesproviding an opening means for the thread end containing a rubbing orfriction tool serving for fraying the thread end at a predeterminedpoint. By this fraying process, the thread end is converted into anopened up condition corresponding very much to the condition of the ringof opened up fibers present in the spinning rotor, so that the piecingstep is substantially improved. The attachment of the opened up threadend to the fiber ring present in the spinning rotor is accomplished sosatisfactorily that thickened portions are practically avoided, whilethe tear strength corresponds extensively to the tear strength in theremaining length of yarn.

In a structurally advantageous embodiment of this invention, the openingmeans contains two clamping zones or points for the thread end, betweenwhich the friction tool is disposed, which tool can be moved adjustablytoward the thread end.

In a further embodiment of the invention, the provision is made that oneof the clamping zones contains two clamping surfaces displaceable withrespect to each other at right angles to the longitudinal direction ofthe thread end. This affords the additional possibility of furtheropening the thread end, by overcoming the spinning twist of the threadend in this area by a mutual shifting of the clamping surfaces. Toensure a flawless engagement of the thread end by the friction tool,another embodiment of the invention provides that a supporting means isarranged oppositely to the friction tool on the other side of the threadend. Advantageously, an air nozzle oriented toward the thread end canserve as the supporting means.

These and further objects, features and advantages of the presentinvention will become more obvious from the following description whentaken in connection with the accompanying drawings which show, forpurposes of illustration only, several embodiments in accordance withthe present invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view of anapparatus constructed in accordance with this invention;

FIGS. 2 and 3 are schematic views depicting another preferred embodimentof opening means for use in the apparatus of FIG. 1 in various operatingpositions;

FIG. 4 is a lateral schematic view of the opening means of FIGS. 2 and3;

FIGS. 5 and 6 are schematic partial views of further preferredembodiments of opening means having friction tools with a reciprocatingdrive, for use in the apparatus of FIG. I;

FIGS. 7 to 10 are schematic partial views of further preferredembodiments of opening means having friction tools with a rotary drive,for use in the apparatus of FIG. I; and

FIG. 11 is a schematic partial view of a further preferred embodiment ofopening means wherein the thread end, in addition to being frayed, isfreed of its spinning twist by untwisting.

DETAILED DESCRIPTION OF THE DRAWINGS Only a spinning rotor 2 of aspinning unit I is shown in FIG. I, to which are continuously fed fibersopened up with the aid of feeding and opening means not shown in detail.These fibers are deposited in the spinning rotor 2 in the form of a ring3. From the spinning rotor 2, a yarn takeoff duct 4 leads toward theoutside; the spun thread is withdrawn via this duct. The spun thread isthen wound up on a windup spool 8 which, during normal operation, restson a windup roll 6 and is driven by the latter.

In the illustrated position, the windup spool 8 is lifted off its winduproll 6 in order to execute a piecing step. The spool is resting on anauxiliary windup roll 7 pertaining to a device, with the aid of whichthe thread 5 is pulled off from the windup spool 8, returned into thespinning rotor 2 via the yarn takeoff duct 4, and can thereafter againbe withdrawn as a spun thread. For this purpose, the auxiliary winduproll 7 can be driven in both directions of rotation.

Before the thread end is returned into the spinning rotor 2, the threadend is prepared and opened up in order to facilitate the piecingoperation. For this purpose, an opening means It) is provided into whichthe thread 5 can be inserted manually or automatically. The openingmeans 10 contains two clamping zones 11 and 12 for the thread 5, betweenwhich a friction tool 13 is arranged which can be adjustably movedtoward the thread 5. The friction tool 13, which rotates in theembodiment of FIG. 1, serves for opening up and severing the thread 5 ata certain location by fraying. The opened up thread end is then offered,by means of the clamping zone 12 arranged on an rocking lever 14, to

the yarn takeoff duct 4 by pivoting this rocking lever about its axle inthe direction of arrow 14a. Via the takeoff duct 4, the thread end isthen sucked into the spinning rotor 2 with the aid of a vacuum. In orderto expose the thread to the friction tool 13 in a tensioned condition,the clamping zone 11 is likewise arranged on a lever 16 pivotable aboutan axle 17. The rocking lever 16 can be spring-biased, for example, sothat the thread is under tensile stress while underneath the frictiontool. As a result of this tensile stress, the partially frayed thread isstill further opened up by stretching and is finally severed with theaid of this stretching effeet.

In FIGS. 2 to 4, an opening means is shown with a reciprocating frictiontool 18 in various views and before and after the use thereof. Thefriction tool 18 which has, for example, an abrading surface roughenedin the manner of a file, rests with its inherent weight on the thread 5.The friction tool is articulated to a lever 19 pulled against a drivableeccentric 21 by means of a spring 20. The eccentric 21 can drive thefriction tool 18 so that it is set into reciprocating motion, wherebythe thread 5 is frayed and finally severed. Lever 19 is pivotallymounted at pivot axle 107. In this connection, the further provision canbe made of equipping the friction tool 18 with an extension 22 fashionedas a blade intended for the final severing of the thread 5. Thisblade-like extension 22 can be shifted, for example, by way of anadditional drive, not shown, into the area of the thread 5 after acertain amount of fraying has been obtained. The drive for the extensioncan be tripped, for instance, after a specific number of revolutions ofthe eccentric 21, corresponding to a specific friction effect.

FIG. 5 shows another reciprocating friction tool 23 having a frictionsurface fashioned like a brush. In the embodiment of FIG. 6, a vibratingmotor 25 is provided as a drive means for a likewise reciprocatingfriction tool 24 which can be coated on its friction surface, forexample, with an emery cloth.

In the construction of FIG. 7, a friction tool 13 fashioned as arotational element in accordance with the embodiment of FIG. 1 isprovided. The direction of rotation of the friction tool 13, whichlatter is driven by way of a shaft in a manner not illustrated indetail, is chosen advantageously so that the friction tool executes apulling motion on the thread end which later on is to be introduced intothe yarn takeoff duct; thus, a certain combing out effect is alsoattainable thereby at the thread end to be opened up. A similarembodiment is shown in FIG. 8 wherein the friction tool 13, which isarranged on a swivel arm in a manner not shown in detail, is driven withthe aid of a gear belt 26 which loops around a gear wheel of a fixedshaft 27. The swivel arm 118 for the friction tool 23 is suitablyfashioned to be pivotablc about the shaft 27. In order to hold the zoneto be frayed securely against the friction tool 13, this embodimentincludes a blast or air jet nozzle 28 arranged on the side of the threadand in opposition to the friction tool.

in the embodiment of FIG. 9, a body of rotation haw ing the shape of amushroom head serves as the friction tool 29; this body is drivendirectly by a small electric motor 30. The friction tool 29 can beshifted together with the motor 30 at right angles to the longitudinaldirection of the thread and 5. In the embodiment of FIG. 10, which issimilar to that of FIG. 9, a cylindrical body is employed as thefriction tool 31, which is driven by a small electric motor 30. Themotor 30 can be adjusted, together with the friction tool 31, in variousinclinations with respect to the longitudinal direction of the thread 5.Thus, different fraying conditions can be chosen (see the position 30and 31 shown in dot-dash lines). This makes it possible, on the onehand, to determine the extent to which the thread is to be opened upwhile, on the other hand, the opening means can be adapted to thedirection of the spinning twist of the thread 5.

In the embodiment of FIG. 11, again a body of rotation is provided asthe friction tool 32, this body having a conical configuration and beingdisposed to be adjustable at right angles to the longitudinal directionof the thread 5. This conical friction tool 32 is provided with frictionsurfaces 32 and 32" differently fashioned over its length so that thepart having the smaller diameter effects a preliminary roughening andthe area with the larger diameter executes a subsequent severing of thethread 5. In the embodiment of FIG. 11, the clamping zone 11 is formedby two clamping jaws 33 and 34 which are mutually displaceable (arrows142, 143) with the aid of a drive means not shown in detail. By themutual shifting of the clamping jaws 33 and 34, the thread 5 is twistedin this zone, whereby the spinning twist still inherent therein can beannulled, so that an even further improved opening effect is obtained.

In all embodiments, the piece of thread remaining in the region of theclamping zone 11 after severing of the thread 5 can be removed by meansof a suction nozzle 9 which is illustrated by way of example in thearrangements of FIGS. 2 and 11. Moreover, it can be advantageous in allembodiments to arrange underneath the thread and in opposition to thefriction tool a supporting device which can be constituted, for example,by a blast nozzle 28 according to FIG. 8 or also by a resilientlymounted support.

While we have shown and described several embodiments in accordance withthe present invention, it is understood that the same is not limitedthereto but is susceptible of numerous changes and modifications asknown to those skilled in the art and we therefore do not wish to belimited to the details shown and described herein but intend to coverall such changes and modifications as are encompassed by the scope ofthe appended claims.

We claim: 1. Apparatus for piecing a thread end in an open-end spinningunit having a spinning rotor with a ring of opened-up fibers comprising:

opening means including friction tool means for fraying the thread andat a predetermined location,

and a device for returning the thread end into the spinning rotor afterfraying thereof by the friction tool means.

2. Apparatus according to claim 1, wherein the opening means includes apair of clamping devices for clamping said thread at respective oppositesides of the predetermined location where said friction tool means frayssaid thread.

3. Apparatus according to claim 2, wherein said opening means includesmeans for moving said friction tool means toward and away from saidthread.

4. Apparatus according to claim 1, wherein said friction tool meansincludes a file member which is driven in a reciprocating motion atright angles to the longitudinal direction of the thread.

5. Apparatus according to claim 1, wherein said friction tool meansincludes a brush member which is driven in a reciprocating motion atright angles to the longitudinal direction of the thread.

6. Apparatus according to claim 3, wherein said friction tool meansincludes a file member which is driven in a reciprocating motion atright angles to the longitudinal direction of the thread.

7. Apparatus according to claim 3, wherein said friction tool meansincludes a brush member which is driven in a reciprocating motion atright angles to the longitudinal direction of the thread.

8. Apparatus according to claim 1, wherein said friction tool meansincludes a body of rotation with a roughened friction surface which isdriven about an axis extending transverse to the longitudinal directionof the thread.

9. Apparatus according to claim 3, wherein said friction tool meansincludes a body of rotation with a roughened friction surface which isdriven about an axis extending transverse to the longitudinal directionof the thread.

10. Apparatus according to claim 8, wherein said axis extends obliquelyto the longitudinal direction of the thread.

11. Apparatus according to claim 10, wherein adjusting means areprovided for adjusting the angular inclination of said axis with respectto the longitudinal direction of the thread to accommodate for thedirection and inclination of spinning fibers forming said thread.

12. Apparatus according to claim 9, wherein said axis extends obliquelyto the longitudinal direction of the thread.

13. Apparatus according to claim 12, wherein adjusting means areprovided for adjusting the angular inclination of said axis with respectto the longitudinal direction of the thread to accommodate for thedirection and inclination of spinning fibers forming said thread.

14. Apparatus according to claim 2, wherein the clamping device disposedon the side of the friction tool means which is closest to the extremefree end of the thread is mounted for movement in the longitudinaldirection of the thread, and wherein means are provided for moving saidlast-mentioned clamping device in said longitudinal direction to effectseparation of said thread at the frayed part thereof.

15. Apparatus according to claim 14, wherein a windup means for saidthread is disposed at a position spaced from said clamping device.

16. Apparatus according to claim 4, wherein the clamping device disposedon the side of the friction tool means which is closest to the extremefree end of the thread is mounted for movement in the longitudinaldirection of the thread, and wherein means are provided for moving saidlast-mentioned clamping device in said longitudinal direction to effectseparation of said thread at the frayed part thereof.

17. Apparatus according to claim 5, wherein the clamping device disposedon the side of the friction tool means which is closest to the extremefree end of the thread is mounted for movement in the longitudinaldirection of the thread, and wherein means are provided for moving saidlast-mentioned clamping device in said longitudinal direction to effectseparation of said thread at the frayed part thereof.

18. Apparatus according to claim 8, wherein the clamping device disposedon the side of the friction tool means which is closest to the extremefree end of the thread is mounted for movement in the longitudinaldirection of the thread, and wherein means are provided for moving saidlast-mentioned clamping device in said longitudinal direction to effectseparation of said thread at the frayed part thereof.

19. Apparatus according to claim 2, wherein one of said clamping devicescontains two clamping surfaces which are mutually displaceable at rightangles to the longitudinal direction of the thread while in a clampedposition for effecting at least partial elimination of the spinningtwist in said thread.

20. Apparatus according to claim 4, wherein one of said clamping devicescontains two clamping surfaces which are mutually displaceable at rightangles to the longitudinal direction of the thread while in a clampedposition for effecting at least partial elimination of the spinningtwist in said thread.

21. Apparatus according to claim 5, wherein one of said clamping devicescontains two clamping surfaces which are mutually displaceable at rightangles to the longitudinal direction of the thread while in a clampedposition for effecting at least partial elimination of the spinningtwist in said thread.

22. Apparatus according to claim 8, wherein one of said clamping devicescontains two clamping surfaces which are mutually displaceable at rightangles to the longitudinal direction of the thread while in a clampedposition for effecting at least partial elimination of the spinningtwist in said thread.

23. Apparatus according to claim 14, wherein one of said clampingdevices contains two clamping surfaces which are mutually displaceableat right angles to the longitudinal direction of the thread while in aclamped position for effecting at least partial elimination of thespinning twist in said thread.

24. Apparatus according to claim 1, wherein a thread supporting deviceis arranged in facing relationship to said friction tool means forsupporting said thread during fraying operations.

25. Apparatus according to claim 4, wherein a thread supporting deviceis arranged in facing relationship to said friction tool means forsupporting said thread during fraying operations.

26. Apparatus according to claim 5, wherein a thread supporting deviceis arranged in facing relationship to said friction tool means forsupporting said thread during fraying operations.

27. Apparatus according to claim 8, wherein a thread supporting deviceis arranged in facing relationship to said friction tool means forsupporting said thread during fraying operations.

28. Apparatus according to claim 24, wherein an air nozzle orientedtoward the thread serves as the supporting device.

29. Apparatus according to claim 1, wherein said friction tool means isa conical file member having differently fashioned friction surfacesover its length with a first friction surface on a smaller diameterportion for effecting a preliminary roughening of the thread and asecond friction surface as a larger diameter portion for executing asubsequent severing of the thread.

1. Apparatus for piecing a thread end in an open-end spinning unithaving a spinning rotor with a ring of opened-up fibers comprising:opening means including friction tool means for fraying the thread endat a predetermined location, and a device for returning the thread endinto the spinning rotor after fraying thereof by the friction toolmeans.
 2. Apparatus according to claim 1, wherein the opening meansincludes a pair of clamping devices for clamping said thread atrespective opposite sides of the predetermined location where saidfriction tool means frays said thread.
 3. Apparatus according to claim2, wherein said opening means includes means for moving said frictiontool means toward and away from said thread.
 4. Apparatus according toclaim 1, wherein said friction tool means includes a file member whichis driven in a reciprocating motion at right angles to the longitudinaldirection of the thread.
 5. Apparatus according to claim 1, wherein saidfriction tool means includes a brush member which is driven in areciprocating motion at right angles to the longitudinal direction ofthe thread.
 6. Apparatus according to claim 3, wherein said frictiontool means includes a file member which is driven in a reciprocatingmotion at right angles to the longitudinal direction of the thread. 7.Apparatus according to claim 3, wherein said friction tool meansincludes a brush member which is driven in a reciprocating motion aTright angles to the longitudinal direction of the thread.
 8. Apparatusaccording to claim 1, wherein said friction tool means includes a bodyof rotation with a roughened friction surface which is driven about anaxis extending transverse to the longitudinal direction of the thread.9. Apparatus according to claim 3, wherein said friction tool meansincludes a body of rotation with a roughened friction surface which isdriven about an axis extending transverse to the longitudinal directionof the thread.
 10. Apparatus according to claim 8, wherein said axisextends obliquely to the longitudinal direction of the thread. 11.Apparatus according to claim 10, wherein adjusting means are providedfor adjusting the angular inclination of said axis with respect to thelongitudinal direction of the thread to accommodate for the directionand inclination of spinning fibers forming said thread.
 12. Apparatusaccording to claim 9, wherein said axis extends obliquely to thelongitudinal direction of the thread.
 13. Apparatus according to claim12, wherein adjusting means are provided for adjusting the angularinclination of said axis with respect to the longitudinal direction ofthe thread to accommodate for the direction and inclination of spinningfibers forming said thread.
 14. Apparatus according to claim 2, whereinthe clamping device disposed on the side of the friction tool meanswhich is closest to the extreme free end of the thread is mounted formovement in the longitudinal direction of the thread, and wherein meansare provided for moving said last-mentioned clamping device in saidlongitudinal direction to effect separation of said thread at the frayedpart thereof.
 15. Apparatus according to claim 14, wherein a windupmeans for said thread is disposed at a position spaced from saidclamping device.
 16. Apparatus according to claim 4, wherein theclamping device disposed on the side of the friction tool means which isclosest to the extreme free end of the thread is mounted for movement inthe longitudinal direction of the thread, and wherein means are providedfor moving said last-mentioned clamping device in said longitudinaldirection to effect separation of said thread at the frayed partthereof.
 17. Apparatus according to claim 5, wherein the clamping devicedisposed on the side of the friction tool means which is closest to theextreme free end of the thread is mounted for movement in thelongitudinal direction of the thread, and wherein means are provided formoving said last-mentioned clamping device in said longitudinaldirection to effect separation of said thread at the frayed partthereof.
 18. Apparatus according to claim 8, wherein the clamping devicedisposed on the side of the friction tool means which is closest to theextreme free end of the thread is mounted for movement in thelongitudinal direction of the thread, and wherein means are provided formoving said last-mentioned clamping device in said longitudinaldirection to effect separation of said thread at the frayed partthereof.
 19. Apparatus according to claim 2, wherein one of saidclamping devices contains two clamping surfaces which are mutuallydisplaceable at right angles to the longitudinal direction of the threadwhile in a clamped position for effecting at least partial eliminationof the spinning twist in said thread.
 20. Apparatus according to claim4, wherein one of said clamping devices contains two clamping surfaceswhich are mutually displaceable at right angles to the longitudinaldirection of the thread while in a clamped position for effecting atleast partial elimination of the spinning twist in said thread. 21.Apparatus according to claim 5, wherein one of said clamping devicescontains two clamping surfaces which are mutually displaceable at rightangles to the longitudinal direction of the thread while in a clampedposition for effecting at least partial elimination of the spinningtwist in said thread.
 22. Apparatus according to clAim 8, wherein one ofsaid clamping devices contains two clamping surfaces which are mutuallydisplaceable at right angles to the longitudinal direction of the threadwhile in a clamped position for effecting at least partial eliminationof the spinning twist in said thread.
 23. Apparatus according to claim14, wherein one of said clamping devices contains two clamping surfaceswhich are mutually displaceable at right angles to the longitudinaldirection of the thread while in a clamped position for effecting atleast partial elimination of the spinning twist in said thread. 24.Apparatus according to claim 1, wherein a thread supporting device isarranged in facing relationship to said friction tool means forsupporting said thread during fraying operations.
 25. Apparatusaccording to claim 4, wherein a thread supporting device is arranged infacing relationship to said friction tool means for supporting saidthread during fraying operations.
 26. Apparatus according to claim 5,wherein a thread supporting device is arranged in facing relationship tosaid friction tool means for supporting said thread during frayingoperations.
 27. Apparatus according to claim 8, wherein a threadsupporting device is arranged in facing relationship to said frictiontool means for supporting said thread during fraying operations. 28.Apparatus according to claim 24, wherein an air nozzle oriented towardthe thread serves as the supporting device.
 29. Apparatus according toclaim 1, wherein said friction tool means is a conical file memberhaving differently fashioned friction surfaces over its length with afirst friction surface on a smaller diameter portion for effecting apreliminary roughening of the thread and a second friction surface as alarger diameter portion for executing a subsequent severing of thethread.